1. Field of the Invention
This invention relates to facsimile and similar apparatus employing solid-state image scanner means and more particularly to such apparatus of the type including a plurality of solid-state image scanners and automatic means for correcting the location of a joint or junction between the picture signals of adjacent image scanners.
2. Description of the Prior Art
Recently, production for commercial applications of solid-state image scanner units of the CCD (charge coupled device), BBD (bucket-brigade device), MOSIC or the like has increased. As a result, plane-scane facsimile apparatuses are becoming prevalent in practical applications. These types of solid-state image scanners usually include either 1,024 or 2,048 bits of photoelements. Accordingly, facsimile apparatuses employing such image scanner means are subject to a definite limitation as to the resolution of picture elements. Under this situation, a method for enabling picture reproduction at the receiver end with an improved resolution has been proposed, in which a plurality of solid-state image scanners are arranged to share each main scan of the original copy with each other (see Japanese Patent Application No. 132,505/77, now open to public inspection as Japanese Laid-open Patent Application No. 66017/54 (1979)).
According to this application, the solid-state image scanners are arranged so that their scan ranges partly overlap each other. These scanners are fed with scan start pulse signals which are preliminarily set in phase according to the spatial arrangement of the image scanners. In writing the picture signal segments from the respective solid-state image scanners in a line memory, the write-in clock is blocked for the duration of the overlap of the scan ranges of adjacent image scanners. That is, the scan start pulse signals are prefixed in phase at the manufacturing stage, in accordance with the spatial arrangement of the solid-state image scanners, to prevent an appearance of any overlapped signal joint or junction within each one-scan-line picture signal.
Such a preadjustment is intended to prevent an occurrence of a seam or seams in the picture which is received. However, such a preadjustment has been found unsatisfactory as the relative spatial arrangement of the CCD image scanners is subtly disturbed with changes in temperature within the apparatus and these changes cause an appearance of a seam or seams in the picture, as received.